Readability awareness in natural language processing systems

ABSTRACT

Electronic natural language processing in a natural language processing (NLP) system, such as a Question-Answering (QA) system. A receives electronic text input, in question form, and determines a readability level indicator in the question. The readability level indicator includes at least a grammatical error, a slang term, and a misspelling type. The computer determines a readability level for the electronic text input based on the readability level indicator, and retrieves candidate answers based on the readability level.

BACKGROUND

Embodiments of the invention generally relate to electronic naturallanguage processing, and more particularly, to identifying readabilitylevels of a user question and natural language documents basedreadability indicators.

Traditional systems estimate a user's reading level by analyzingrelatively large datasets, associated with the user, over severaliterations. The more text samples that are analyzed, the more likelythat the analysis yields reliable results. For example, some metricsthat these systems use are: average word length and average words persentence.

SUMMARY

According to an aspect of the invention, a method is provided forelectronic natural language processing in an electronic natural languageprocessing system. The method receives an electronic text input, anddetermines a readability level indicator of the electronic text input.The readability level indicator includes at least one of a grammaticalerror, a slang term, and a misspelling type in the electronic textinput. The method determines a readability level of the electronic textinput based on the readability level indicator.

According to a further aspect of the invention, a computer system forelectronic natural language processing is provided. The system includesone or more computer devices each having one or more processors and oneor more tangible storage devices, and a program embodied on at least oneof the one or more storage devices. The program has a plurality ofprogram instructions for execution by the one or more processors. Thesystem receives an electronic text input, and determines a readabilitylevel indicator of the electronic text input. The readability levelindicator includes at least one of a grammatical error, a slang term,and a misspelling type in the electronic text input. The systemdetermines a readability level of the electronic text input based on thereadability level indicator.

According to a further aspect of the invention, a computer programproduct for electronic natural language processing is provided. Thecomputer program product includes a non-transitory tangible storagedevice having program code embodied therewith. The program code isexecutable by a processor of a computer to perform a method. The methodreceives an electronic text input, and determines a readability levelindicator of the electronic text input. The readability level indicatorincludes at least one of a grammatical error, a slang term, and amisspelling type in the electronic text input. The method determines areadability level of the electronic text input based on the readabilitylevel indicator.

According to a further aspect of the invention, a method for electronicnatural language processing in an electronic natural language processingsystem, is provided. The method receives a set of natural languagedocuments and determines readability level indicators in the set ofnatural language documents. The method provides, in response toreceiving a query text, at least one natural language document whosereadability level is within a threshold distance of a readability levelof the query text. The readability level of the query text is based onone or more readability level indicators including at least one of agrammatical error, a slang term, and a misspelling type in the querytext.

According to a further aspect of the invention, a computer system forelectronic natural language processing, is provided. The system includesone or more computer devices, each having one or more processors and oneor more tangible storage devices, and a program embodied on at least oneof the one or more storage devices. The program has a plurality ofprogram instructions for execution by the one or more processors. Thesystem receives a set of natural language documents and determinesreadability level indicators in the set of natural language documents.The system provides, in response to receiving a query text, at least onenatural language document whose readability level is within a thresholddistance of a readability level of the query text. The readability levelof the query text is based on one or more readability level indicatorsincluding at least one of a grammatical error, a slang term, and amisspelling type in the query text.

According to a further embodiment of the invention, a computer programproduct for electronic natural language processing is provided. Thecomputer program product includes a non-transitory tangible storagedevice having program code embodied therewith. The program code isexecutable by a processor of a computer to perform a method. The methodreceives a set of natural language documents and determines readabilitylevel indicators in the set of natural language documents. The methodprovides, in response to receiving a query text, at least one naturallanguage document whose readability level is within a threshold distanceof a readability level of the query text. The readability level of thequery text is based on one or more readability level indicatorsincluding at least one of a grammatical error, a slang term, and amisspelling type in the query text.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a natural language processing (NLP)computing environment, according to an embodiment of the invention.

FIG. 2 is a flow chart of a method for analyzing a text input in the NLPcomputing environment of FIG. 1, according to an embodiment of theinvention.

FIG. 3 is a block diagram of a natural language processing (NLP)computing environment, according to an embodiment of the invention.

FIG. 4 is a flowchart of a method for analyzing a text input in the NLPcomputing environment of FIG. 4, according to an embodiment of theinvention.

FIG. 5 is a functional block diagram of a question-answering system,according to an embodiment of the invention.

FIG. 6 is a functional block diagram of a cloud computing node, such asthe computing systems in FIGS. 1 and 3, according to an embodiment ofthe invention.

FIG. 7 is a functional block diagram of an illustrative cloud computingenvironment, including the cloud computing node of FIG. 6, according toan embodiment of the invention.

FIG. 8 is a functional block diagram of functional layers of the cloudcomputing environment of FIG. 7, according to an embodiment of theinvention.

DETAILED DESCRIPTION

It may be desirable for a natural language processing (NLP) system, suchas a Question-Answering (QA) system, to tailor its answers to a userbased on the user's reading and comprehension ability. That is, althoughthe QA system may have the correct answer to the user's question, theuser may not understand the answer because there is potentially amismatch between the user's reading level and the answer's readabilitylevel.

Consider, for example, a lay user interested in learning more about anillness whose study is highly specialized. The user may ask the QAsystem: “What causes X?”, where “X” is an illness whose study is highlyspecialized. A traditional QA system may retrieve several answers thatrepresent the most relevant, rich, and up-to-date content associatedwith illness X. However, assume that the answers are found in a highlytechnical scientific journal. The layperson is unlikely to have thepre-requisite knowledge, reading ability, or comprehension level, tounderstand the answers. In some circumstances, therefore, what may beconsidered as the best answer under some criteria (for example,relevance and completeness) may not be the best answer for a given user.That is, the user may find it more helpful to receive answers that,while less robust, are easier to grasp.

Accordingly, embodiments of the invention provide a method, system, andcomputer program product, for electronic natural language processing(NLP) on an NLP system. Embodiments of the invention may be deployed onone or more computers in an NLP computing environment, to executeinstructions of a program to carry out a method. The instructions may bestored on one or more tangible storage devices of the NLP computingsystem. The tangible storage device may be part of, or operativelyconnected to, the computer.

According to an aspect of the invention, a user may provide the NLPsystem with a single sentence, which may be in the form of a question.The NLP system may analyze the text to estimate the user's readingability, and to tailor its responses to the text based on the identifiedreading level.

According to an aspect of the invention, the NLP system may determinethe user's readability level based on relatively small text samples.Some embodiments may determine the readability level of a singlesentence or smaller text fragments.

FIG. 1 is a functional block diagram of an NLP computing environment100, according to an embodiment of the invention. NLP computingenvironment 100 includes a computer 102 having a processor 104, and aprogram 106 stored on a tangible storage device of computer 102.Instructions of program 106 may be executable by processor 104. Program106 may include a set of instructions for parsing electronic textinputs; this set of instructions is referred to as a parser. Additionaldetails of these components, according to embodiments of the invention,are provided in connection with FIGS. 6-8, below.

Generally, computer 102 may receive an electronic text input (forexample, from a user) and provide one or more texts in response toreceiving the electronic text input. In one embodiment, the receivedelectronic text input may be in the form of a question, and textprovided in response may be in the form of an answer to that question. Aquestion may have one or more answers, and an answer may be responsiveto one or more questions. This is for illustration purposes only, anddoes not limit embodiments of the invention; the received electronictext input need not be a question, and the text provided in responseneed not be an answer. In one example, the received electronic textinput may be an answer and the text provided in response may be aquestion.

Generally, texts used by computer 102 (be they questions or answers) maybe defined as having corresponding readability characteristics, orfeatures, that define the texts' readability levels. A readabilitylevels refers to a grouping of texts based on common or predefinedreadability characteristics or features.

Examples of readability characteristics or features include, withoutlimitation: number of words; number of words other than common words;average word length; number of words found exclusively in a particulardictionary (for example, a technical dictionary may have words not foundin other dictionaries; using words found in the technical dictionary maysuggest a readability level corresponding to a high educationalachievement classification); and use of passive voice.

Examples of readability levels include, without limitation: grade levels(for example, 1-12 grades, undergraduate levels, etc.); professionalrole or expertise (for example, professor, lawyer, scientist); absolutenumerical scores (for example, a range of 0 to 1); and relativenumerical scores (for example, −1 to 1).

Data used to define and determine readability levels and readabilitycharacteristics may be stored in one or more databases 110 operativelyconnected to computer 102. These include, in the depicted embodiment, atext corpus 110A database, a slang corpus 110B database, a spellingcorpus 110C, and a questions corpus 110D database. Computer 102 may useinformation in these databases to analyze the question to determine itsreadability characteristics, and to determine one or more appropriateanswers.

Text corpus 110A may include one or more texts of various lengths havingassociated readability levels and readability characteristics. Theseproperties may be predefined, or determined periodically. Readabilitycharacteristics of texts stored in text corpus 110A may be used, byembodiments of the invention, as reference points for identifyingreadability characteristics of other texts analyzed by computer 102.

In one example, text corpus 110A may include text derived from variousdata sources, including, for example, the Internet, and any data that ismanually provided or automatically scanned (for example, by a webcrawler). Texts in text corpus 110A may include formal and informaltexts, each having a defined set of readability characteristics.

In one example, formal text may be defined as text having readabilitycharacteristics that are the same as, or similar to, text used in theCommon Cores Standards by the National Governors Association Center forBest Practices and the Council of Chief State School Officers (“CommonCore”). In a further example, informal text may be defined as texthaving readability characteristics that are the same as, or similar to,text used in blogs, community forums, and social media platforms. Thespecific characteristics that identify a given text as formal orinformal depend on specific implementations of the invention, and may bedefined differently from one embodiment to another. Furthermore, theirrespective definitions may evolve over time based on changes in languageusage.

In one embodiment, computer 102 may periodically or continuously monitorvarious data sources (such as the Internet) to analyze and/or collectvarious text corpora and to assess their readability characteristics.Computer 102 may assign these texts corresponding readability levels.Computer 102 may use text corpus 110A as a reference point in evaluatingother texts.

Slang corpus 110B may include words, phrases, or other text that isdefined as slang. According to an aspect of the invention, slang termsmay be defined as readability characteristics associated with variousreadability levels. In one embodiment, this information may beencapsulated in a slangs table including a listed of slang terms havingassociated readability characteristics, such as readability scores. Forexample, the term “aint't” may be defined as a slang term, and may beassigned an associated readability level, or an associated readabilityscore (for example, (−0.1)), or both. In this example, appearance of theterm “ain't” may contribute a (−0.1), in the question may contribute ascore of (−0.1) to the overall score of the question. In an embodiment,the slang term may be identified as an abbreviation of a wordcorresponding to an acronym associated with the word in a collection oftext messaging acronyms.

Computer 102 may use various rules to determine readability levels ofthe question and the answer based on slang terms. In one embodiment, theimpact of slang terms in the question may be based on an aggregation ofthe scores of all slang terms appearing in the question. In anotherembodiment, an average may be used. In another embodiment, only thehighest score in absolute value may be used. In an embodiment, the mereoccurrence of a slang term in a question may result in the questionreceiving a readability level without use of readability scores. Otherrules are possible.

Spelling corpus 110C may include definitions of various misspellingtypes along with associated effects on readability levels of a giventext. Computer 102 may analyze a user's question to identify whichmisspelling types appear in the question, and to evaluate the effect ofthe identified misspelling types on the question's readability level.

For example, one misspelling type may be one in which a misspelledletter appears within a predefined distance from the correct letter on akeyboard (the distance may be measured, in one embodiment, as the numberof keys between the correct letter and the misspelled letter). This typeof misspelling may be assigned a negative readability score that isrelatively insignificant, since it may be more indicative of the user'styping ability than the user's educational level (the educational levelbeing measured through the readability level). As a further example,some words in a question may be misspelled because the user hasrelatively little experience with seeing the word in written form,suggesting that the question (and by proxy, the user posing it) has arelatively low readability level. For example, using “their” whenintending “there” may be an indication of a relatively low readabilityscore.

Examples of additional misspelling types include: long versus shortwords (misspelling short words may have a higher impact on readabilitylevel than misspelling long words); word sophistication; word usagestatistics in texts having associated readability characteristics;number of auto-corrections of the input text during the text inputprocess (a question may have no misspellings once the user submits thequestion, but the question intake process may have included severalauto-corrections of misspelled words). In an embodiment, the misspellingmay correspond to a phonetic reading of the word that differs from itscorrect spelling.

Questions corpus 110D may include one or more questions havingassociated readability levels and readability characteristics.Readability levels and characteristics for questions in this corpus maybe similarly defined and associated as described above in connectionwith text corpus 110A. In one embodiment, questions may be added to thiscorpus based on outputs of program 106 derived as a consequence ofexecuting one or more steps of method 200 (FIG. 2) executed by program106. Iterative executions of method 200 may yield results that may beused to train a model. The trained model may be used as a point ofreference in evaluating other questions in future iterations of method200. For example, similarities between a new question, and several oldquestions having the same readability score, may increase the likelihoodthat method 200 assigns the readability score of the old questions tothe new question.

Additional embodiments of the invention may include one or moredatabases that may be used to determine the readability level of thequestion. These may include, without limitation, a technical database(having a list of technical terms and associated impact of using thoseterms on the question's score); sophisticated words (some words arelikely to be known by users having a minimum readability level).

FIG. 2 is a flowchart of a method 200 for electronic natural languageprocessing in NLP computing environment 100 (FIG. 1), according to anembodiment of the invention. Steps of method 200 may be embodied asinstructions of program 106 on the tangible storage device of computer102 and executed by processor 104 (FIG. 1).

Referring now to FIGS. 1 and 2, computer 102 may receive an electronictext input, which may be in the form of a question (hereinafter, “thequestion”). Computer 102 may receive the question from an electronicinput source. The electronic input source may be operatively connectedto computer 102. The operational connectivity may be local to computer102 (for example, a keyboard or other input/output (I/O) source), or aremote (for example, a network communication on a distributed or cloudcomputing platform), or a combination thereof.

Computer 102 may parse the received question to determine itsconstituents and their respective properties (at 204). In oneembodiment, computer 102 may use a deep parsing technique, such as anEnglish Slot Grammar (ESG) parser and a predicate-argument structure(PAS) builder. With these tools, computer 102 may generate one or moreparse trees for the question (each tree may be scored based on a scoringcriteria).

Based on the parsing/deep parsing operations (at 204), computer 102 mayprocess the question to determine a readability level indicator for thequestion. Computer 102 may determine the readability level indicator, inone instance, by identifying one or more grammatical errors in thequestion (at 208). Each type of grammatical error may be assigned acorresponding score that determines its impact on the readability scoreof the question. For example, computer 102 may identify one or more ofthe following grammatical errors: lack of subject/verb agreement (forexample, “I jumps”); possessive mistakes (for example, “men's” versus“mens”; wrong but phonetically similar word choice (“you're” versus“your”); and many others. Some grammatical errors may be considered moresignificant than others, and their corresponding scores may reflect thisconsideration.

Computer 102 may further identify a readability level indicator byidentifying a slang term in the question (at 212). A slang termappearing in a question may be defined as indicative of a relatively lowreadability score. Accordingly, a slang term may be assigned acorresponding readability score that lowers the question's overallreadability score. Computer 102 may consult slang corpus 110B todetermine whether a given word in the question is a slang term.

In one example, if the question includes the term “ain't” rather than“is not”, computer 102 may detect that “ain't” is a slang term, and thatits use suggests a lower readability level for the user asking thequestion than might otherwise have been the case. If this slang term hasan associated negative readability score, computer 102 may apply thisscore to the question, as defined by corresponding rules, as describedabove. If the slang term has an associated readability level, computer102 may apply this readability level to the question, as defined bycorresponding rules, as described above.

Computer 102 may further identify a readability level indicator byidentifying a misspelling in the question and further identifying acorresponding misspelling type (at 212). A misspelling appearing in aquestion may be defined as indicative of a relatively low readabilityscore. Accordingly, misspellings may be assigned to categories or types,and corresponding scores that lower the question's overall readabilityscore. Computer 102 may identify misspellings by consulting anelectronic dictionary, and may consult spelling corpus 110C to determinethe misspelling type and its impact on the question's readability level.

Computer 102 may determine a readability score (or a readability level)for the question based on determining the readability level indicator(at 220). Computer 102 may determine the readability level byconsidering one or more of the readability level indicators thatcomputer 102 determines throughout steps of method 200. For example,computer 102 may consider any one or more of grammatical errors,misspelling types, and slang term usage in the question. Depending onthe particular rules that computer 102 applies, these indicators may begiven equal or disparate treatment.

In one embodiment, computer 102 may determine the readability level byanalyzing individual readability scores for the question (based ongrammatical errors, misspelling types, slang term usage, or acombination thereof), to arrive at a final readability level. In anotherembodiment, computer 102 may compare the determined readability scores(or the readability characteristics) for the question with readabilityscores/characteristics of various texts in text corpus 110A.

In one example, the question may be assigned the readability level of atext with which the question shares a predetermined number ofreadability characteristics (for example, both the question and the textuse the same slang term in conjunction with the same misspelling type).

FIG. 3 is a block diagram of a natural language processing (NLP)computing environment 300, according to an embodiment of the invention.Aspects of NLP computing environment 300 are similar to NLP computingenvironment 100 (FIG. 1), and like elements bearing a reference numberin the (100) range are similarly numbered in the (300) range. However,like numbering does not necessarily require like functionality.

Generally, NLP computing environment 300 includes a computer 302 havinga processor 304, and a program 306 stored on a tangible storage deviceof computer 302. Instructions of program 306 may be executable byprocessor 304. Program 306 may include a set of instructions for parsingelectronic text inputs; this set of instructions is referred to as aparser. Additional details of these components, according to embodimentsof the invention, are provided in connection with FIGS. 6-8, below.

Generally, computer 302 receives electronic natural language documentsfor processing according to their readability levels, and to providesuch documents, or portions thereof, in response to receiving an input(for example, from a user). For example, computer 302 generally mayreceive natural language documents in a text corpus, index the documentsaccording to their features, including their readability indicators, anddetermine their readability levels. In an embodiment, computer 302 maydetermine readability levels for portions of documents.

Generally, natural language documents processed by computer 302 may bedefined as having corresponding readability characteristics, orfeatures, that define the texts' readability levels. A readability levelrefers to a grouping of texts based on common or predefined readabilitycharacteristics or features.

Examples of readability characteristics or features include, withoutlimitation: number of words per sentence; number of words other thancommon words; average word length; number of words found exclusively ina particular dictionary (for example, a technical dictionary may havewords not found in other dictionaries; using words found in thetechnical dictionary may suggest a readability level corresponding to ahigh educational achievement classification); grammatical constructionof a sentence pertaining to, for example, the number of subordinatingconjunctions or the noun phrase depth; and use of passive voice.

Examples of readability levels include, without limitation: grade levels(for example, 1-12 grades, undergraduate levels, etc.); professionalrole or expertise (for example, professor, lawyer, scientist); absolutenumerical scores (for example, a range of 0 to 1); and relativenumerical scores (for example, −1 to 1).

Data used to define and determine readability levels and readabilitycharacteristics may be stored in one or more databases 310 operativelyconnected to computer 302. These include, in the depicted embodiment, atext corpus 310A database, a slang corpus 310B database, a spellingcorpus 310C, and a questions corpus 310D database. Computer 302 may useinformation in these databases to analyze the question to determine itsreadability characteristics, and to determine one or more appropriateanswers.

Text corpus 310A may include one or more texts of various lengths havingassociated readability levels and readability characteristics. Computer302 may periodically receive and process natural language documents forstoring in text corpus 310A. Readability characteristics of texts storedin text corpus 310A may be used, by embodiments of the invention, asreference points for identifying readability characteristics of othertexts analyzed by computer 302.

In one example, text corpus 310A may include text derived from variousdata sources, including, for example, the Internet, and any data that ismanually provided or automatically scanned (for example, by a webcrawler). Texts in text corpus 310A may include formal and informaltexts, each having a defined set of readability characteristics.

In one example, formal text may be defined as text having readabilitycharacteristics that are the same as, or similar to, text used in theCommon Cores Standards by the National Governors Association Center forBest Practices and the Council of Chief State School Officers (“CommonCore”). In a further example, informal text may be defined as texthaving readability characteristics that are the same as, or similar to,text used in blogs, community forums, and social media platforms. Thespecific characteristics that identify a given text as formal orinformal depend on specific implementations of the invention, and may bedefined differently from one embodiment to another. Furthermore, theirrespective definitions may evolve over time based on changes in languageusage.

In one embodiment, computer 302 may periodically or continuously monitorvarious data sources (such as the Internet) to analyze and/or collectvarious text corpora and to assess their readability characteristics.Computer 302 may assign these texts corresponding readability levels.Computer 102 may use text corpus 310A as a reference point in evaluatingother texts.

Slang corpus 130B may include words, phrases, or other text that isdefined as slang. According to an aspect of the invention, slang termsmay be defined as readability characteristics associated with variousreadability levels. In one embodiment, this information may beencapsulated in a slangs table including a listed of slang terms havingassociated readability characteristics, such as readability scores. Forexample, the term “aint't” may be defined as a slang term, and may beassigned an associated readability level, or an associated readabilityscore (for example, (−0.1)), or both. In this example, appearance of theterm “ain't” in the question may contribute a net effect of (−0.1) tothe overall score of the question.

Computer 302 may use various rules to determine readability levels ofthe question and the answer based on slang terms. In one embodiment, theimpact of slang terms in the question may be based on an aggregation ofthe scores of all slang terms appearing in the question. In anotherembodiment, an average may be used. In another embodiment, only thehighest score in absolute value may be used. In an embodiment, the mereoccurrence of a slang term in a question may result in the questionreceiving a readability level without use of readability scores. Otherrules are possible.

Spelling corpus 310C may include definitions of various misspellingtypes along with associated effects on readability levels of a giventext. Computer 302 may analyze a user's question to identify whichmisspelling types appear in the question, and to evaluate the effect ofthe identified misspelling types on the question's readability level.

For example, one misspelling type may be one in which a misspelledletter appears within a predefined distance from the correct letter on akeyboard (the distance may be measured, in one embodiment, as the numberof keys between the correct letter and the misspelled letter). This typeof misspelling may be assigned a negative readability score that isrelatively insignificant, since it may be more indicative of the user'styping ability than the user's educational level (the educational levelbeing measured through the readability level). As a further example,some words in a question may be misspelled because the user hasrelatively little experience with seeing the word in written form,suggesting that the question (and by proxy, the user posing it) has arelatively low readability level. For example, using “their” whenintending “there” may be an indication of a relatively low readabilityscore.

Examples of additional misspelling types include: long versus shortwords (misspelling short words may have a higher impact on readabilitylevel than misspelling long words); word sophistication; word usagestatistics in texts having associated readability characteristics; andnumber of auto-corrections of the input text during the text inputprocess (a question may have no misspellings once the user submits thequestion, but the question intake process may have included severalauto-corrections of misspelled words).

Questions corpus 310D may include one or more questions havingassociated readability levels and readability characteristics.Readability levels and characteristics for questions in this corpus maybe similarly defined and associated as described above in connectionwith text corpus 310A. In one embodiment, questions may be added to thiscorpus based on outputs of program 306 derived as a consequence ofexecuting one or more steps of method 200 (FIG. 2) executed by program306. Iterative executions of method 200 may yield results that may beused to train a model. The trained model may be used as a point ofreference in evaluating other questions in future iterations of method200. For example, similarities between a new question, and several oldquestions having the same readability score, may increase the likelihoodthat method 200 assigns the readability score of the old questions tothe new question.

Additional embodiments of the invention may include one or moredatabases that may be used to determine the readability level of thequestion. These may include, without limitation, a technical database(having a list of technical terms and associated impact of using thoseterms on the question's score); sophisticated words (some words arelikely to be known by users having a minimum readability level).

FIG. 4 is a flowchart of a method 400 for electronic NLP processing byan electronic NLP system, according to an embodiment of the invention.Steps of method 400 may be embodied as instructions of program 306 onthe tangible storage device of computer 302 and executed by processor304 (FIG. 3).

Referring now to FIGS. 3 and 4, steps of method 400 will now bedescribed in connection with NLP computing environment 300. Computer 302receives a set of electronic natural language documents (step 402) froma document source, such as text corpus 310A, another database.Alternatively, computer 302 may receive documents returned by a searchengine in response to a query. The process of receiving documents foranalysis may be referred to as “ingestion.”

Computer 302 determines (step 406) readability levels for the set ofnatural language documents that it has received (step 402) by detectingand evaluating readability level indicators in the documents, such asindicators that determine the document's formality or informality. Thereadability level indicators that computer 302 may consider are varied,and may differ from one embodiment of the invention to another. In oneembodiment, the readability level indicators include one or more of agrammatical error, a slang term, and a misspelling. Other factors thatmay be considered include: average inverse-document-frequency (IDF) ofwords given a formal reference text corpus; average IDF of words given anon-formal text corpus; average word length; a normalized count of thenumber words per document; number of words per sentence; a normalizedcount of the number characters per document; number of characters persentence; number verbs, nouns, adverbs, or other word types persentence; and number of instances of passive voice, gerunds, or othersyntax used per sentence.

In an embodiment, computer 302 may associate a readability levelindicator detected in a given natural language document (step 406) withthe specific portion of that document in which the indicator isdetected. This allows computer 302 to classify portions of a givendocument differently, via other steps of method 400.

In an embodiment, computer 302 may determine (step 406) the readabilitylevel of a document based in part on whether the language used in agiven document is formal or informal. In one example, formal text may bedefined as text having readability characteristics that are the same as,or similar to, text used in the Common Cores Standards by the NationalGovernors Association Center for Best Practices and the Council of ChiefState School Officers (“Common Core”). In a further example, informaltext may be defined as text having readability characteristics that arethe same as, or similar to, text used in blogs, community forums, andsocial media platforms. The specific characteristics that identify agiven text as formal or informal depend on specific implementations ofthe invention, and may be defined differently from one embodiment toanother. Furthermore, their respective definitions may evolve over timebased on changes in language usage.

In an embodiment, the determination that a document is formal orinformal may be based, in part, on results of periodic or continuousanalysis of documents from various data sources (such as the Internet),which analyze and/or collect various text corpora and to assess theirreadability characteristics. Computer 302 may assign these textscorresponding readability levels to indicate their level of formality.Computer 302 may use text corpus 310A as a reference point in evaluatingother texts during successive processing.

In an embodiment, determining a document's readability level may beperformed using, in part, a support machine vector (SMV) classifier,which takes into account grammatical and syntactic features of lexicalitems in the document.

Computer 302 provides (step 410), in response to a query text, at leastone natural language document, or a portion of a natural languagedocument, whose readability level is within a threshold distance of areadability level of the query text. As part of this process, computer302 receives a query text (for example, a question from a user), anddetermines a corresponding readability level for the query text.Computer 302 queries text corpus 310A to identify natural languagedocuments that may serve as candidate answers (or candidate documents toprovide in response to the input text). In doing so, computer 302considers not only a given document's relevance to the query text, butalso its readability level.

In providing (410) at least one natural language document, or a portionthereof, in response to the query text, computer 302 may determine thequery text's readability level based on a readability level indicator inthe query text, including at least one of a grammatical error, a slangterm, and a misspelling type in the query text. In an embodiment,determining the query text's readability level may be based onretrieving an assigned readability level of the query text (for example,a given query text may be defined as having a particular readabilitylevel; this may be useful in training data models). In an embodiment,determining the query text's readability level may be based on executingmethod 200 (FIG. 2). In an embodiment, determining the query text'sreadability level may be based on retrieving a stored readability levelpreviously determined for the query text.

In one embodiment, computer 302 provides (step 410) a natural languagedocument in response to the query text only where the two have anidentical readability level. In another embodiment, computer 302provides a document whose readability level is within a definedthreshold distance from the query text's readability level (i.e., adifference in readability values). In another embodiment, computer 302provides a ranked list of natural language documents, where the rankingis based on the readability level of the documents. In an embodiment,the readability level of a natural language document to be provided isone of several factors that determines its rank, or whether it isprovided at all in response to the query text.

In an embodiment, computer 302 provides (step 410), in response to thequery text, a set of documents having a score that measures both theirrelevance and readability level, where the score matches a definedcriteria. For example, only the top 5 scoring documents may be returned.As a further example, all documents whose score meet a defined thresholdvalue may be returned. The score may be defined, in one embodiment, asthe solution to Function 1, a function defined as:

score(q,d)=V(q)·V(d)/|V(q)|·α·1/|complexity_(q)−complexity_(d)|

-   -   α=hyperparameter        where (q) represents a query text, and (d) represents a        candidate natural language document; V(q) and V(d) represent        respective binary vectors of words (or other elements) in the        query text and the candidate document; (a) is a tuning        parameter, and complexity_(q) and complexity_(d) represent        readability levels that computer 302 determines for each of the        query text and the candidate document. For each document        analyzed, computer 302 may evaluate a pairing of the query text        and the document according to this score function. Computer 302        may then provide the user with documents whose score is within a        defined threshold value.

Referring to an example (“Example 1”) that illustrates operation ofmethod 400, as described above, computer 302 may receive a set ofnatural language documents from a database for processing. The documentsin this example may relate to the healthcare domain. The documents mayinclude formal text documents, such as medical text books, scientificjournals, medical dictionaries, and other documents using language thatis defined as formal. The documents may also include informal text, suchas blog posts, online forum discussions, and other text, which may beidentified as having an author who is not a recognized medicalprofessional, or whose expressed language does not meet formalityrequirements.

Continuing with Example 1, computer 302 identifies readability levelindicators in the medical-domain natural language documents that it hasreceived. For example, computer 302 determines that a given document isformal or informal, and whether it belongs to a certain level (forexample, the document is at the readability level of an uneducatedperson, a lay person, a medical student, a medical professional, amedical expert, etc.).

Continuing with Example 1, computer 302 receives a query text (forexample, the question “is exercising recommended for MS patients?” froma user. Computer 302 analyzes the query text to identify readabilityindicators, such as misspellings, slang terms, or grammatical errors, todetermine the user's likely readability level. Computer 302 queries textcorpus 310A to retrieve answers that, while relevant, are of anappropriate readability level for the user. This process provides theuser with information that the user can understand, because, to theuser, an unintelligible answer may be as useless as a wrong answer.

In other steps of method 400 (not shown), according to embodiments ofthe invention, computer 302 may perform one or more of the followingfunctions. In an embodiment, computer 302 may train a data model oversuccessive iterations of method 400 to determine readability levels fora natural language document or a query text. For example, a naturallanguage document having a particular set of readability indicators maybe defined as belonging to a particular reading level. The particularset of readability indicators may be defined based on a common (oraverage, median, or other measure of commonality) set of readabilityindicators of all or a subset of the documents in that reading level. Asmore documents or query texts are added to respective data models, thedata models may be updated to reflect characteristics of the addedmaterial.

In an embodiment, steps of method 400 may be performed as part of aprocessing pipeline in a question-and-answering (QA) system. Method 400may be executed in multiple parallel instances, and its results may bescored and ranked. Other pipelines in the QA system may provide computer302 with their outputs, and computer 302 may provide the outputs of themethod 400 processing pipelines to other pipelines in the QA system.

In an embodiment, in response to receiving an answer from computer 302,a user may indicate whether the provided answer(s) is intelligible tothe user. Computer 302 may receive this indication from the user basedon a variety of indicators, such as a user interface component operableby the user (for example, a button labeled “this answered my question”),or a subsequent action taken by the user (for example, the useractivates a functionality that is expected only if the user would haveunderstood the answer).

In an embodiment, computer 302 may assign different readability levelsto different portions of a given natural language document. A portion ofa natural language document may include, without limitation, a term,phrase, clause, sentence, paragraph, page, chapter, volume, edition, orother grouping of natural language text.

FIG. 5 is a functional block diagram of a question-answering (QA) systempipeline 500 that may be deployed on NLP system 100 (FIG. 1) or NLPsystem 300 (FIG. 3), according to embodiments of the invention.Referring now to FIG. 5, QA system pipeline 500 processes an inputquestion in accordance with one illustrative embodiment. It should beappreciated that the stages of the QA system pipeline 500 shown in FIG.5 are implemented as one or more software engines, components, or thelike, which are configured with logic for implementing the functionalityattributed to the particular stage. Each stage is implemented using oneor more of such software engines, components or the like. The softwareengines, components, etc. are executed on one or more processors of oneor more data processing systems or devices and utilize or operate ondata stored in one or more data storage devices, memories, or the like,on one or more of the data processing systems. The QA system pipeline500 of FIG. 5 is augmented, for example, in one or more of the stages toimplement the improved mechanism of the illustrative embodimentsdescribed hereafter, additional stages may be provided to implement theimproved mechanism, or separate logic from the QA system pipeline 500may be provided for interfacing with the QA system pipeline 500 andimplementing the improved functionality and operations of theillustrative embodiments.

As shown in FIG. 5, the QA system pipeline 500 comprises a plurality ofstages 510-580 through which the QA system operates to analyze an inputquestion and generate a final response. In an initial question inputstage 510, the QA system receives an input question that is presented ina natural language format. That is, a user inputs, via a user interface,an input question for which the user wishes to obtain an answer, e.g.,“Who are Washington's closest advisors?” In response to receiving theinput question, the next stage of the QA system pipeline 500, i.e. thequestion and topic analysis stage 520, parses the input question usingnatural language processing (NLP) techniques to extract major featuresfrom the input question, and classify the major features according totypes, e.g., names, dates, or any of a plethora of other defined topics.For example, in the example question above, the term “who” may beassociated with a topic for “persons” indicating that the identity of aperson is being sought, “Washington” may be identified as a proper nameof a person with which the question is associated, “closest” may beidentified as a word indicative of proximity or relationship, and“advisors” may be indicative of a noun or other language topic.

In addition, the extracted major features include key words and phrasesclassified into question characteristics, such as the focus of thequestion, the lexical answer type (LAT) of the question, and the like.As referred to herein, a lexical answer type (LAT) is a word in, or aword inferred from, the input question that indicates the type of theanswer, independent of assigning semantics to that word. For example, inthe question “What maneuver was invented in the 1500s to speed up thegame and involves two pieces of the same color?,” the LAT is the string“maneuver.” The focus of a question is the part of the question that, ifreplaced by the answer, makes the question a standalone statement. Forexample, in the question “What drug has been shown to relieve thesymptoms of ADD with relatively few side effects?,” the focus is “drug”since if this word were replaced with the answer, e.g., the answer“Adderall” can be used to replace the term “drug” to generate thesentence “Adderall has been shown to relieve the symptoms of ADD withrelatively few side effects.” The focus often, but not always, containsthe LAT. On the other hand, in many cases it is not possible to infer ameaningful LAT from the focus.

Referring again to FIG. 5, the identified major features are then usedduring the question decomposition stage 530 to decompose the questioninto one or more queries that are applied to the corpora ofdata/information 545 in order to generate one or more hypotheses. Thequeries are generated in any known or later developed query language,such as the Structure Query Language (SQL), or the like. The queries areapplied to one or more databases storing information about theelectronic texts, documents, articles, websites, and the like, that makeup the corpora of data/information 545. That is, these various sourcesthemselves, different collections of sources, and the like, represent adifferent corpus 547 within the corpora 545. There may be differentcorpora 547 defined for different collections of documents based onvarious criteria depending upon the particular implementation. Forexample, different corpora may be established for different topics,subject matter categories, sources of information, or the like. As oneexample, a first corpus may be associated with healthcare documentswhile a second corpus may be associated with financial documents.Alternatively, one corpus may be documents published by the U.S.Department of Energy while another corpus may be IBM Redbooks documents.Any collection of content having some similar attribute may beconsidered to be a corpus 547 within the corpora 545.

The queries are applied to one or more databases storing informationabout the electronic texts, documents, articles, websites, and the like,that make up the corpus of data/information. The queries are applied tothe corpus of data/information at the hypothesis generation stage 540 togenerate results identifying potential hypotheses for answering theinput question, which can then be evaluated. That is, the application ofthe queries results in the extraction of portions of the corpus ofdata/information matching the criteria of the particular query. Theseportions of the corpus are then analyzed and used, during the hypothesisgeneration stage 540, to generate hypotheses for answering the inputquestion. These hypotheses are also referred to herein as “candidateanswers” for the input question. For any input question, at this stage540, there may be hundreds of hypotheses or candidate answers generatedthat may need to be evaluated.

The QA system pipeline 500, in stage 550, then performs a deep analysisand comparison of the language of the input question and the language ofeach hypothesis or “candidate answer,” as well as performs evidencescoring to evaluate the likelihood that the particular hypothesis is acorrect answer for the input question. As mentioned above, this involvesusing a plurality of reasoning algorithms, each performing a separatetype of analysis of the language of the input question and/or content ofthe corpus that provides evidence in support of, or not in support of,the hypothesis. Each reasoning algorithm generates a score based on theanalysis it performs which indicates a measure of relevance of theindividual portions of the corpus of data/information extracted byapplication of the queries as well as a measure of the correctness ofthe corresponding hypothesis, i.e. a measure of confidence in thehypothesis. There are various ways of generating such scores dependingupon the particular analysis being performed. In general, however, thesealgorithms look for particular terms, phrases, or patterns of text thatare indicative of terms, phrases, or patterns of interest and determinea degree of matching with higher degrees of matching being givenrelatively higher scores than lower degrees of matching.

Thus, for example, an algorithm may be configured to look for the exactterm from an input question or synonyms to that term in the inputquestion, e.g., the exact term or synonyms for the term “movie,” andgenerate a score based on a frequency of use of these exact terms orsynonyms. In such a case, exact matches will be given the highestscores, while synonyms may be given lower scores based on a relativeranking of the synonyms as may be specified by a subject matter expert(person with knowledge of the particular domain and terminology used) orautomatically determined from frequency of use of the synonym in thecorpus corresponding to the domain. Thus, for example, an exact match ofthe term “movie” in content of the corpus (also referred to as evidence,or evidence passages) is given a highest score. A synonym of movie, suchas “motion picture” may be given a lower score but still higher than asynonym of the type “film” or “moving picture show.” Instances of theexact matches and synonyms for each evidence passage may be compiled andused in a quantitative function to generate a score for the degree ofmatching of the evidence passage to the input question.

Thus, for example, a hypothesis or candidate answer to the inputquestion of “What was the first movie?” is “The Horse in Motion.” If theevidence passage contains the statements “The first motion picture evermade was ‘The Horse in Motion’ in 1878 by Eadweard Muybridge. It was amovie of a horse running,” and the algorithm is looking for exactmatches or synonyms to the focus of the input question, i.e. “movie,”then an exact match of “movie” is found in the second sentence of theevidence passage and a highly scored synonym to “movie,” i.e. “motionpicture,” is found in the first sentence of the evidence passage. Thismay be combined with further analysis of the evidence passage toidentify that the text of the candidate answer is present in theevidence passage as well, i.e. “The Horse in Motion.” These factors maybe combined to give this evidence passage a relatively high score assupporting evidence for the candidate answer “The Horse in Motion” beinga correct answer.

It should be appreciated that this is just one simple example of howscoring can be performed. Many other algorithms of various complexitiesmay be used to generate scores for candidate answers and evidencewithout departing from the spirit and scope of the present invention.

In the synthesis stage 560, the large number of scores generated by thevarious reasoning algorithms are synthesized into confidence scores orconfidence measures for the various hypotheses. This process involvesapplying weights to the various scores, where the weights have beendetermined through training of the statistical model employed by the QAsystem and/or dynamically updated. For example, the weights for scoresgenerated by algorithms that identify exactly matching terms and synonymmay be set relatively higher than other algorithms that are evaluatingpublication dates for evidence passages. The weights themselves may bespecified by subject matter experts or learned through machine learningprocesses that evaluate the significance of characteristics evidencepassages and their relative importance to overall candidate answergeneration.

The weighted scores are processed in accordance with a statistical modelgenerated through training of the QA system that identifies a manner bywhich these scores may be combined to generate a confidence score ormeasure for the individual hypotheses or candidate answers. Thisconfidence score or measure summarizes the level of confidence that theQA system has about the evidence that the candidate answer is inferredby the input question, i.e. that the candidate answer is the correctanswer for the input question.

The resulting confidence scores or measures are processed by a finalconfidence ranking stage 570, which compares the confidence scores andmeasures to each other, compares them against predetermined thresholds,or performs any other analysis on the confidence scores to determinewhich hypotheses/candidate answers are the most likely to be the correctanswer to the input question. The hypotheses/candidate answers areranked according to these comparisons to generate a ranked listing ofhypotheses/candidate answers (hereafter simply referred to as “candidateanswers”). From the ranked listing of candidate answers, at stage 580, afinal answer and confidence score, or final set of candidate answers andconfidence scores, are generated and output to the submitter of theoriginal input question via a graphical user interface or othermechanism for outputting information.

In the feature-merging approach, there is no way to know what exactlythe contribution of an individual passage is to ultimately judgingwhether a candidate answer is or is not the correct answer. This causessome loss in the overall signal, at best. The loss is likely tointensify when the passages are to be viewed as supporting for thecorrectness of the proposition underlying a non-factoid question, suchas a “yes-no” question.

The illustrative embodiments take advantage of the polar nature ofsupporting passages, namely, that any passage either justifies orrefutes the candidate answer as the correct answer to the question. Notethat this holds for both factoid and “yes-no” questions being the focusof the QA pipeline. On that basis, the QA system reinterprets the set ofsupporting passages returned by the search component. Then, in atraining setting, the QA system builds a model specifically adjusted tothe partitioning of the passages returned by the search.

The passage sets are associated with different candidate answers.Without feature merging, the QA system cannot train the model within thetraditional passage scoring framework. Still, the QA system knows forany given passage set which of the possible alternate scenarios appliesto it as a whole: this set of passages does not support the candidateanswer as being the correct answer. This judgment is based purely onconsulting the ground truth and does not rely on or assume textualoccurrence of a candidate answer in a passage. Consequently, thatpassage still is a potential source of features for a learner.

Instead of feature merging, final confidence ranking stage 570 retainsthe individuality of supporting passages as a set of evidence thatcollectively contributes signal to the learner. Each passage is aninstance for a classifier, which labels an entire passage set assupports or does not support the correct answer, and even if the learnerdoes not have the instance labels on a per-instance basis, the learnerknows the label for the entire set of instances.

Rather than training a supervised learning model from feature vectorsderived from passages, multiple instance learned model 590 is trained toperform a different classification task: that of assigning a binarylabel to a set of supporting passages where the sets do have labels.

The illustrative embodiments propose a shift of granularity of passageassessment and scoring, where on the one hand, passage feature vectorsdo not get merged (and labeled), and on the other, the feature vectorsare for the entire set, containing many passage vectors unlabeled, whichthe machine learning system seeks to label. This shift of granularityrepositions the classification task to one or more appropriate formultiple instance learning. Given a set of labeled sets of passagesretrieved by search queries, the machine learning system learns how tolabel sets and, in effect, distinguishes between correct and incorrectanswer candidates, without knowing the actual polarity of the individualsupporting passages within the sets, resulting in multi-instance learnedmodel 590.

In essence, the illustrative embodiments recast the problem of passagescoring and hypothesis assessment for candidate answers to actually takeadvantage of the fact that the machine learning system only possessesincomplete knowledge about how training examples should be labeled.

At runtime for a given input question 510, final confidence rankingstage 570 receives candidate answers with passage sets from hypothesisand evidence scoring stage 550 and synthesis stage 560. Final confidenceranking stage uses multi-instance learned model 590 to establish true orfalse for each candidate answer using a set of feature vectorscorresponding to multiple instances of passages that support or refutethe candidate answer.

Referring now to FIGS. 1-2 and 5, according to an embodiment of theinvention, NLP system 100 may perform one or more steps of method 200using one or more processing stages 510-590 of QA system pipeline 500.In one embodiment, QA system pipeline 500 may receive an electronic textinput, in question form, at input question stage 510 (step 204), anddetermine readability indicators in the question, including grammaticalerrors, misspellings, or slang terms, and a corresponding readabilitylevel for the question, at one or more of step 208, step 212, and step220, in one or more of stages 520-590 in the pipeline.

Based on the question's determined readability level, QA system pipeline500 may, at one or more stages in the processing pipeline, filter textsin corpora 545 based on readability levels of documents (or portions ofdocuments) in the corpora.

In an embodiment, filtering of documents (or portions of documents)based on their readability levels is performed relatively early in theprocessing pipeline. This approach may have the advantage of reducingthe amount of processing performed at later stages in the pipeline byreducing the number of texts that are used to generate hypotheses andsupporting evidence. For example, the filtering may be performed at thequestion decomposition stage 530, where QA system pipeline 500 generatesqueries for application to corpora 545 to retrieve text that can then beused to generate hypotheses in stage 540. The queries may be applied, atstage 530, to fewer than every corpus 547 in corpora 545. For example,if a given corpus 547 (or individual documents, or portions thereof) hasa readability level that differs from the question's readability levelby more than a threshold value, the given corpus 547 may be excludedfrom the processing performed at stage 530. The readability level usedfor the given corpus 547, to determine whether it should be filtered,may be a single readability level associated with the entire corpus, ordetermined by considering readability levels of the various documents inthe corpus (or portions thereof). In one example, the readability levelused may be the average or median readability level of the documents inthe corpus. In a related embodiment, the determination as to whether toinclude, or exclude, a given document or sets of documents may beperformed on a case-by-case basis.

In another embodiment, filtering of documents (or portions documents)based on their readability levels is performed relatively late in theprocessing pipeline. This approach may have the advantage of consideringtexts, at least initially, regardless of their readability levels, toarrive at the most relevant and accurate answer, and to applyreadability level considerations as an additional consideration duringthe later stage. This approach allows QA system pipeline 500 to weighrelevance and accuracy considerations against readability levelconsiderations at a processing stage where QA system pipeline 500 hasgathered all the necessary data to make an informed decision. In oneexample, QA system pipeline 500 may perform later-stage filtering at thefinal confidence ranking stage 570 or final answer and confidence stage580. That is, prior to outputting (for example, prior to displayinganswers to a user), QA system pipeline 500 may, at stage 570, consideran answer's readability level, alone or in conjunction with itsrelevance to the question, in ranking the answer. Additionally, oralternatively, QA system pipeline 500 may, at stage 580, filter from thepotential answers to the question any answer whose readability leveldiffers from that of the question by more than a threshold value,regardless of ranking operations at stage 570.

In other embodiments, filtering may be performed at one or more stagesother than those described above. Additionally, filtering may beperformed during multiple processing stages. In a related embodiment,filtering may be performed by the same stage in QA system pipeline asthe stage that executes Function 1, described above in connection withFIGS. 3-4.

Referring now to FIG. 6, a schematic of an example of a cloud computingnode 10 (which may be, for example, computer 102 in FIG. 1, or computer302 in FIG. 3) is shown. Cloud computing node 10 is only one example ofa suitable cloud computing node and is not intended to suggest anylimitation as to the scope of use or functionality of embodiments of theinvention described herein. Regardless, cloud computing node 10 iscapable of being implemented and/or performing any of the functionalityset forth hereinabove.

In cloud computing node 10 there is a computer system/server 12, whichis operational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 12 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, hand-held or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 12 may be described in the general context ofcomputer system-executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 12 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 6, computer system/server 12 in cloud computing node 10is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 12 may include, but are not limitedto, one or more processors or processing units 16, a system memory 28,and a bus 18 that couples various system components including systemmemory 28 to processor 16.

Bus 18 represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnects (PCI) bus.

Computer system/server 12 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 12, and it includes both volatileand non-volatile media, removable and non-removable media.

System memory 28 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. Computer system/server 12 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 34 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 18 by one or more datamedia interfaces. As will be further depicted and described below,system memory 28 may include at least one program product having a set(e.g., at least one) of program modules that are configured to carry outthe functions of embodiments of the invention.

Program/utility 40, having a set (at least one) of program modules 42,may be stored in system memory 28 by way of example, and not limitation,as well as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 42 generally carry out the functions and/ormethodologies of embodiments of the invention as described herein.

Computer system/server 12 may also communicate with one or more externaldevices 14 such as a keyboard, a pointing device, a display 24, etc.;one or more devices that enable a user to interact with computersystem/server 12; and/or any devices (e.g., network card, modem, etc.)that enable computer system/server 12 to communicate with one or moreother computing devices. Such communication can occur via Input/Output(I/O) interfaces 22. Still yet, computer system/server 12 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 20. As depicted, network adapter 20communicates with the other components of computer system/server 12 viabus 18. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 12. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

Referring now to FIG. 7, illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 comprises one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 54B, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 7 are intended to be illustrative only and that cloud computingnodes 10 and cloud computing environment 50 can communicate with anytype of computerized device over any type of network and/or networkaddressable connection (e.g., using a web browser).

Referring now to FIG. 8, a set of functional abstraction layers providedby cloud computing environment 50 (FIG. 7) is shown. It should beunderstood in advance that the components, layers, and functions shownin FIG. 8 are intended to be illustrative only and embodiments of theinvention are not limited thereto. As depicted, the following layers andcorresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include: mainframes 61; RISC(Reduced Instruction Set Computer) architecture based servers 62;servers 63; blade servers 64; storage devices 65; and networks andnetworking components 66. In some embodiments, software componentsinclude network application server software 67 and database software 68.

Virtualization layer 70 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers71; virtual storage 72; virtual networks 73, including virtual privatenetworks; virtual applications and operating systems 74; and virtualclients 75.

In one example, management layer 80 may provide the functions describedbelow. Resource provisioning 81 provides dynamic procurement ofcomputing resources and other resources that are utilized to performtasks within the cloud computing environment. Metering and Pricing 82provide cost tracking as resources are utilized within the cloudcomputing environment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal 83 provides access to the cloud computing environment forconsumers and system administrators. Service level management 84provides cloud computing resource allocation and management such thatrequired service levels are met. Service Level Agreement (SLA) planningand fulfillment 85 provide pre-arrangement for, and procurement of,cloud computing resources for which a future requirement is anticipatedin accordance with an SLA.

Workloads layer 90 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation 91; software development and lifecycle management 92; virtualclassroom education delivery 93; data analytics processing 94;transaction processing 95; natural language processing 96, includingthose described in connection with FIGS. 1-4, above.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

What is claimed is:
 1. A method for electronic natural languageprocessing in an electronic natural language processing (NLP) system,comprising: receiving a plurality of natural language documents;determining readability level indicators in the plurality of naturallanguage documents; and providing, in response to receiving a querytext, at least one natural language document whose readability level iswithin a threshold distance of a readability level of the query text,wherein the readability level of the query text is based on one or morereadability level indicators including at least one of a grammaticalerror, a slang term, and a misspelling type in the query text.
 2. Themethod of claim 1, further comprising: training a data model based ondetermining the readability level for the one or more of the pluralityof natural language documents.
 3. The method of claim 1, wherein furthercomprising: receiving an electronic text input from a user; querying,based on the electronic text input, a database storing the plurality ofnatural language documents; and retrieving a set of candidate answers inresponse to the query, wherein a candidate answer comprises at least aportion of a natural language document.
 4. The method of claim 3,further comprising: identifying the received electronic text input as aquestion.
 5. The method of claim 3, wherein the NLP system comprises aquestion-answering (QA) pipeline having a plurality of processingstages, wherein one or more of steps of the method are performed by oneor more of the plurality of processing stages, the method furthercomprising: filtering one or more natural language documents, by atleast one processing stage, to exclude one or more natural languagedocuments from processing by at least one other processing stage.
 6. Themethod of claim 3, wherein retrieving a set of candidate answers inresponse to the query comprises: defining a score function having as aninput at least a readability level, wherein the set of candidate answerscomprise natural language documents whose score meets a threshold value.7. The method of claim 1, wherein determining a readability level forone or more of the plurality of natural language documents based onrespective readability level indicators comprises: determining areadability level for at least two portions of at least one naturallanguage document.
 8. The method of claim 1, wherein a score assigned tothe query text is based on at least the misspelling type, wherein themisspelling type comprises one or more of: a misspelling in a wordfalling within a defined range; a misspelling of a word, where the wordis found in at least one dictionary, and not found in at least anotherdictionary; and a number of auto-corrections detected during an inputprocess for the query text, the input process comprising receiving thequery text from a user via an input device.
 9. A computer system forelectronic natural language processing (NLP), comprising: one or morecomputer devices each having one or more processors and one or moretangible storage devices; and a program embodied on at least one of theone or more storage devices, the program having a plurality of programinstructions for execution by the one or more processors, the programinstructions comprising instructions for: receiving a plurality ofnatural language documents; determining readability level indicators inthe plurality of natural language documents; and providing, in responseto receiving a query text, at least one natural language document whosereadability level is within a threshold distance of a readability levelof the query text, wherein the readability level of the query text isbased on one or more readability level indicators including at least oneof a grammatical error, a slang term, and a misspelling type in thequery text.
 10. The system of claim 9, wherein the program instructionsfurther comprise program instructions for: training a data model basedon determining the readability level for the one or more of theplurality of natural language documents.
 11. The system of claim 9,wherein the program instructions further comprise program instructionsfor: receiving an electronic text input from a user; querying, based onthe electronic text input, a database storing the plurality of naturallanguage documents; and retrieving a set of candidate answers inresponse to the query, wherein a candidate answer comprises at least aportion of a natural language document.
 12. The system of claim 11,wherein the program instructions further comprise program instructionsfor: identifying the received electronic text input as a question. 13.The system of claim 12, wherein the NLP system comprises aquestion-answering (QA) pipeline having a plurality of processingstages, wherein one or more of steps of the method are performed by oneor more of the plurality of processing stages, the program instructionsfurther comprising instructions for: filtering one or more naturallanguage documents, by at least one processing stage, to exclude one ormore natural language documents from processing by at least one otherprocessing stage.
 14. The system of claim 11, wherein the programinstructions further comprise program instructions for: defining a scorefunction having as an input at least a readability level, wherein theset of candidate answers comprise natural language documents whose scoremeets a threshold value.
 15. The system of claim 9, wherein the programinstructions for determining a readability level for one or more of theplurality of natural language documents based on respective readabilitylevel indicators comprise program instructions for: determining areadability level for at least two portions of at least one naturallanguage document.
 16. A computer program product for electronic naturallanguage processing, comprising a non-transitory tangible storage devicehaving program code embodied therewith, the program code executable by aprocessor of a computer to perform a method, the method comprising:receiving, by the computer, a plurality of natural language documents;determining, by the computer, readability level indicators in theplurality of natural language documents; and providing, by the computer,in response to receiving a query text, at least one natural languagedocument whose readability level is within a threshold distance of areadability level of the query text, wherein the readability level ofthe query text is based on one or more readability level indicatorsincluding at least one of a grammatical error, a slang term, and amisspelling type in the query text.
 17. The computer program product ofclaim 16, wherein the method further comprises: training, by thecomputer, a data model based on determining the readability level forthe one or more of the plurality of natural language documents.
 18. Thecomputer program product of claim 16, wherein the method furthercomprises: receiving, by the computer, an electronic text input from auser; querying, by the computer, based on the electronic text input, adatabase storing the plurality of natural language documents; andretrieving, by the computer, a set of candidate answers in response tothe query, wherein a candidate answer comprises at least a portion of anatural language document.
 19. The computer program product of claim 18,wherein the method further comprises: identifying, by the computer, thereceived electronic text input as a question.
 20. The computer programproduct of claim 19, wherein the NLP system comprises aquestion-answering (QA) pipeline having a plurality of processingstages, wherein one or more of steps of the method are performed by oneor more of the plurality of processing stages, the method furthercomprising: filtering, by the computer, one or more natural languagedocuments, by at least one processing stage, to exclude one or morenatural language documents from processing by at least one otherprocessing stage.